Abstract: FR-PO654

Lack of Diabetic Glomerulosclerosis in Patients with Longstanding Diabetic Complications

Session Information

Category: Diabetes

  • 502 Diabetes Mellitus and Obesity: Clinical

Authors

  • Mottl, Amy K., University of North Carolina, Chapel Hill, Chapel Hill, North Carolina, United States
  • Basgen, John M., Charles Drew University, Los Angeles, California, United States
  • Hogan, Susan L., University of North Carolina, Chapel Hill, Chapel Hill, North Carolina, United States
  • Nicholas, Susanne B., University of California, Los Angeles, California, United States
  • Jennette, J. Charles, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina, United States
  • Klein, Ronald, University of Wisconsin-Madison, Madison, Wisconsin, United States
  • Mauer, Michael, University of Minnesota, Minneapolis, Minnesota, United States
Background

There is heterogeneity of renal complications in diabetes. We sought to determine the nephropathologic light microscopic characteristics and ultrastructural measurements in adults with type 2 diabetes undergoing research protocol kidney biopsy.

Methods

Inclusion criteria included type 2 diabetes ≥5 years duration, retinopathy and/or microalbuminuria or decreased estimated glomerular filtration rate (GFR) <60ml/min/1.73m2. Nineteen participants (mean age 54y) underwent kidney biopsy, measured GFR using iohexol clearance, first morning void (FMV) urine albumin:creatinine ratio (UACR) and retinal photography. Nephropathologic characteristics were scored by a nephropathologist using usual methods. Stereologic ultrastructural parameters included glomerular basement membrane (GBM) thickness (measured using orthogonal methods) and fractional volume of mesangium (V/v(mes/glom). Typical diabetic glomerulosclerosis was diagnosed if V/v(mes/glom) exceeded 0.20 with GBM thickening (>470nm for women; >520nm for men). Predominant diabetic vasculopathy was diagnosed if V/v(mes/glom) was less than 0.20 in the presence of arterial hyalinosis and/or arteriosclerosis and GBM thickening. Arteriosclerosis without GBM thickening was attributed to nondiabetic arterionephrosclerosis.

Results

Results (see table) showed that 5 of 19 participants had nondiabetic arterionephrosclerosis, and while there were trends in the degree of albuminuria and retinopathy severity, this alone did not distinguish between diabetic and nondiabetic vasculopathy, nor the severity of vasculopathy.

Conclusion

Molecular studies aimed at deciphering between diabetic and nondiabetic complications will require research protocol kidney biopsies from patients with a wide spectrum of clinical disease characteristics.

Funding

  • NIDDK Support